The Graphic Arts industry is already aware of various methods and apparatus for maneuvering sheets from a stack and placing them into a gatherer, so that a book or magazine can be formed by a series of sheets stacked on each other, all in a conventional and already known manner. Taking individual sheets from various stacks of sheets and collecting or gathering the individual sheets together on a gatherer is the commonly known collating activity such as that shown in U.S. Pat. Nos. 2,279,269 and 2,817,513 and 3,176,976 and 4,200,275, for examples. These patents show the collating process whereby various previously folded sheets are nested and gathered together into one unit. However, complicated and slow speed methods and apparatus are utilized in the prior art collating systems, and, in that regard, the present invention improves upon the heretofore known methods and apparatus by providing a high speed method and apparatus which can handle the sheets at a high speed and accurately and continuously collect or collate the sheets from various stacks, all as desired. The prior art commonly requires sheet grippers, of either the mechanical or pneumatic operating type which require extreme precision and complexity of apparatus in order to handle the folded sheet and unfold it and place the sheet on a gathering chain or the like, and the aforesaid patents, along with U.S. Pat. No. 2,626,074, are examples of the complex and highly detailed prior art methods and apparatus heretofore known in the collating function.
Accordingly, the present invention distinguishes over the prior art in that it provides a high speed method and apparatus for collecting or collating folded sheets which are originally available in various stacks of sheets and which can be collected in a single unit or assembly of a sheet from each of the stacks.
Further, the present invention provides a method and apparatus for opening folded sheets and ultimately collating the opened sheets and it does so by moving the sheets in one straightline direction and not requiring that the sheets be moved in various directions or even in any arcuate direction after the sheet has reached a guide which opens the sheet. Further, the guide and all apparatus for opening the sheet are stationary and have no moving parts and only the sheet moves relative to the guide and is thereby opened for placement and positioning on a gathering chain of a conventional nature. Accordingly, the present invention permits a high speed handling of the sheets and it achieves the required continuous operation and accuracy of sheet placement and it accomplishes all of these supreme objectives without requiring any complicated and detailed apparatus.
A further object of this invention is to provide a method and apparatus for collating, or opening folded sheets and collecting them into a unit, wherein already existing delivery cylinders with grippers can be utilized for taking individual sheets from a stack of folded sheets. That is, the already existing delivery drum can be utilized, and the sheet will be taken from the prior art drum and led on through utilization of the method and apparatus of the present invention. Therefore, equipment already in existence need not be discarded and instead can be utilized with the present invention.